In the logistics sector, decarbonisation is no longer a cosmetic option but a regulatory and commercial necessity. As the CSRD (Corporate Sustainability Reporting Directive) comes into force, companies must provide accurate accounts of their environmental impact. At the heart of this exercise lies a technical dilemma: should you use default emission factors or invest in collecting real-world data?
During a carbon audit, this choice determines not only the reliability of your report but also your ability to steer a genuine transition.
1. Understanding the Two Approaches
Default Emission Factors (Top-Down)
Default factors are industry averages provided by databases such as ADEME (Base Empreinte) or the GLEC Framework. They allow emissions to be estimated based on spend-based ratios or distance-based averages.
- Example: Using the average fuel consumption of a 40-tonne heavy goods vehicle (HGV) to estimate emissions for a journey without knowing the exact consumption of the vehicle used.
Real-World Data (Bottom-Up)
Real-world (or primary) data comes directly from the activity itself. This includes actual fuel consumption (in litres), warehouse energy bills, or telematics data from hauliers.
- Example: Calculating the footprint based on the 450 litres of diesel actually consumed by a specific truck on a given journey.
2. What Auditors Demand Today
During a Scope 3 audit (the most critical for logistics), auditors are no longer satisfied with vague estimates. Here’s what they scrutinise:
The Hierarchy of Evidence
Auditors apply a quality hierarchy. Verifiable real-world data (tachograph downloads, invoices) will always carry more weight than an estimate. If you use default factors, you must justify why primary data is not available.
Representativeness and Granularity
An audit requires data to be representative of the period and geographical scope. In logistics, this means:
- Differentiating between engine types (Euro VI vs. Electric).
- Accounting for vehicle load factors.
- Including empty running kilometres.
3. The Risks of Using Default Factors in an Audit
While default factors make it easier to get started, they pose significant risks for a mature company:
- Overstating your footprint: Default factors are often conservatively high. You risk reporting a larger footprint than is actually the case.
- Inability to demonstrate progress: If you upgrade your fleet but continue to use national averages, your decarbonisation efforts will not be reflected in your official reports.
- Market penalties: Shippers now demand precise data for their own reporting. Inaccurate data can disqualify you from tenders.
4. Transitioning to Real-World Data: The Action Plan
To meet the demands of a rigorous audit, the logistics industry must undergo a digital transformation:
- Digitise data collection: Connect your Transport Management Systems (TMS) and telematics tools to centralise consumption data.
- Engage with subcontractors: Since transport is often outsourced, it is crucial to include environmental data-sharing clauses in your contracts.
- Use compliant platforms: Opt for calculation solutions that conform to the GLEC Framework or the ISO 14083 standard, as this will make the auditor's job easier.
Conclusion: From Compliance to Competitive Advantage
A carbon audit should not be seen as a mere administrative burden. Admittedly, the requirement for real-world data demands a structural effort, but it offers unprecedented visibility into the operational efficiency of your supply chain.
By moving from default factors to real-world data, you are not just passing an audit: you are regaining control of your energy performance and positioning yourself as a trusted partner in a low-carbon economy.